Engraving machine



Dec. 18, 1951 BACHMANN 2,579,290

' ENGRAVING MACHINE Filed June 30, 1945 10 Sheets-Sheet 1 Dec. 18, 1951 i o. BACHMANN 2,579,290

ENGRAVING MACHINE Filed June 9 l0 Sheets-Sheet 2 Fig. 2

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ENGRAVING MACHINE Filed June 30, 1945 i0 Sheets-Sheet 4 fig. 9

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ENGRAVING MACHINE Filed June 50, 1945 10 Sheets-Sheet 5 Dec. 18, 1951 o. BACHMAN'N ENGRAVING MACHINE l0 Sheets-Sheet 6 I Filed June 30, 1945 Dec. 18, 1951 Filed June 50, 1945 O. BACH M AN N ENGRAVING MACHINE 10 Sheets-Sheet '7 Dem 18, 1951 Filed June 50, 1945 o. BACHMANN ENGRAVING MACHINE 10 Sheets-Sheet e ill Dec. 18, 1951 o. BACHNIANN 2,579,290

ENGRAVING MACHINE Filed June 30, 1945 10 Sheets-Sheet 9 manic 'Dec. 18, 1951 o. BACHMANN ENGRAVING MACHINE l0 Sheets-Sheet 10 Filed June 50, 1945 Patented Dec. 18, 1951 UNITED STATES PATENT OFFICE ENGRAVING MACHINE;

Oscar Baclimami, Zurich, Switzerland Application June 30, 1945, Serial No. 602,615

Iii Switzerland May 16, 1944 7 2 Claims.

The" present invention relates to a newa'nd improved engraving machine and especially to a device for the produetion of plates of metal, glass and so on bearing a pattern of fine lines which plates after etching are employed for printing the pattern on paper; for instance, to produce polychromatic impressions.

The machine comprises a table for a plate to receive the pattern to be reproduced and at least one engraving stylus, the said plate and said stylus'beihg moved with reference to each other in such a manner; theta great variety of curves of 'a highly or'riamental character may be pro- The main object of the invention consists in the provision of means to produce at will at any position of any of the patterns produced distortions of the curves not easily to be detected and copied.

The invention is applicable for instance to the i i'roduction of bank notes and the like documents.

Iii the accompanying drawings a machine is show'h by Way of an example in a diagrammatic manner.- I

Fig. i is aside elevation of the machine.

Fig. 2 is atop view thereof.

Figs; 3 to are sections respectively on the lihes- 3-'3; 44 and 5-5 of Fig. 1 showing details of construction.

Fig. 6 is a section taken on the line G- -G of Fi 2.

Tillust'rate's the table of the machine in top view;

Fig. 8 is a cross-section taken on line 8-8 of Fig 14 Figs. 9' to 11 are cross-sectionstaken on the lines B -9, Ill-4B and ll--l|, respectively, of Fig. l.-

Fig's. 12 and 13 are cross-sections taken on the linesl2-l2 and I3I3 of Fig. 10.

Fig. 14 is a top view of a cross-support.

Figs.- 15 and 16 are side elevation and plan, respectively, of a device to produce rosettes. v

Fig. 17 shows part of the driving gear in a diagraiiihiatic manner.

Figs. 18 to 55 illustrate by example some of the patterns to be produced by the new machine.

The machine comprises a support carrying a table I; On the table I a slide 2 is mounted; it may beadjuste'd thereon in the direction of the arrows B, Fig.- 2. The slide 2 rests on two parallel ribs 3 with slanting sides on rollers 4 iotatamy rhounted on studs obliquely mounted on ribs on the table I. obliquely mounted studs on the slide 2 rollers 3 are rotatably mounted supporting a cross-slide l. The latter moves at right angles with reference to the movement of slide 2. Both slides may be moved independently of each other as described later. Below the slide 2 an annular frame 8 is arranged which keyed on the shaft 9 (Figs. 2, 3, '7 and 8). On the frame 8 a disk [2 is rotatably mounted which may be fixed to the guide 8 by means of a clampmg screw bolt with not N! (Fig? 3) The disk I2 is provided with rows of holes [3 (Figs. 3 and '7) into each of which may be inserted a springy holder M for a plate IS on which the engravings are to be produced. The plate I5 may consist of metal; glass or any other suitable material covered by a layer of soft material such as wax. The annular frame 8 is provided with a radially projecting flange IS on which a template l! is fastened. The template ll controls themovemeht of the slide I80, which is shown on 4;

The shaft 9 is driven by a motor l9 (Fig. 1) arranged in the frames. The motor [9 drives astepped pulley 2! by a belt 20. The pulleyzl is keyed on a shaft 23 (Fig. 9) rotatably mount ed in the walls 22 or a change speed gear casing. A spur whee 24 Oil the Shaft 23 dilVeS a spin whee125 (Figs.- 9,- 10 and 12) fastened to a hollow shaft 26. Oil the shaft 25 second spur wheel 21 is keyed while a set of toothed gears 28 to 36 of different diameters run loosely on said shaft 26.- The boss of each gear 28 to 3B is provided with a keyway 38 running in axial direction-. In the keywa-y st of each of the spur Wheels 23 to 36 a key 39 maybe inserted. The key 39 is rok-ingly mounted in a recess of a shaft 6.!) slidably lifiolinted in the asm bore of the 15101- 10W shaft 26. Th key 39 projects through a slot 4! of the shaft 26 and is brought in engagemerit with the Kyw'ay 38 of an of the gears 23 to as by a spring according to the axial displaeineh't of the shaft 40. The latter may be displaced by hand by means ot a knob 42 (Fig.

10). The gears 28 to 36 (Figs. 10 and 12') drive by means of intermediate gears 43 spur wheels 44 to B2 keyed on a shaft 54. supiiorted on h shajed member 43 (Fig; 12). The shaft 54 which is journalled the walls 22 carries two spur wheels 5-5, at (Fig. 10) rig-idly connected with each other and axially displaceable on a key of the shaft 54 by a hollow shaft 51 slidingly mounted on Shaft 54. 51 is slidably mounted the wall 22 arid may be axially dis laced by a knob 58 so that the gear 55 may be brought mesh with the spur The gears 43 are The shaft Wheel 60 or the wheel 56 with the spur wheel 6I (Fig. 11). The wheels 60, 6I are keyed on a common shaft 62 rotatably mounted in the walls 22 of the gear case and carrying a worm 63. The latter is in engagement with worm wheel 64 (Figs. 11 and 13) fastened on the shaft 9. The shaft 9 which is journalled in the table I is provided with a key 65 and with a pinion 66. The annular frame 8 is mounted on the said shaft 9 by means of spokes, which are not shown, and is driven thereby by the key 65.

In place of the annular frame 8 the device shown in Figs. '7 and 8 may be used. This device comprises a carriage 'II running in guideways I2 on the table I. On the lower side of the carriage 'II a rack I3 is mounted with which the pinion 66 of shaft 9 is in engagement. The rack I3 may be adjusted with reference to the carriage II by a set screw I4. On the carriage II rests a plate I5 which may be rotated around a stud I6 and which may be arrested in its position by the screw bolts TI. The position of the plate 15 with reference to the carriage Il may. be read off on a scale 18. On the carriage II a template I9 is fastened. The template I9 controls the same movements asdoes the template II. In the walls 22 another shaft 80 is rotatably mounted (Figs. 10 and 12) on which a pair of spur wheels 8|, 82 and two bevel gears 83, 84 are mounted. The spur wheels 8|, 82 are rigidly connected with each other; they slide on a key of the shaft 80 and are rotatably connected with a hollow shaft 85, fitted with the knob 86, which is axially movable but not turnable in the wall 22. The other end of the shaft 80 is connected by a catch with a shaft 81, having a knob 89 by which the shaft 81 and therewith the shaft 80 can be axially displaced to bring either of the bevel gears 83, 84 in or out of mesh with the gear 90. The latter is fixed on a shaft 9I running in bearings 92 of the table I (Figs. 1 and 10). On the shaft 9| two spur wheels 93, 94 are slidably mounted which may be brought in mesh with spur gears 95, 96 (Fig. 1) respectively mounted on a shaft 91. A lever not shown shifts the wheels 93, 94. The shaft 91 runs in bearings 92, 98 of a support I00. The shaft 91 comprises two parts which are axially displaceable with reference to each other but are connected with each otherby a key and turn together.

In the support I (Figs. 1, 2 and 4 to 6) a vertical shaft [M is rotatably mounted. Said shaft IN is connected by a pair of bevelgears I02 with the shaft 91. The support I00 rests, by means of rollers I03 mounted on inclined studs, on rails I04 on the table I The shaft IOI is connected by two pairs of bevel gears I05, I06 andan intermediate shaft with a shaft I01 (Figs. 1, 2, 5 and 6). On the shaft I0I an eccentric chuck I08 is mounted. Said chuck comprises a screw threaded spindle I09 rotatably mounted in bearings of the chuck I08 and provided with a knob at each end for turning said spindle I09 by hand. On the latter a cross-slide III] is arranged having two studs I I I on which a ring H2 is rotatably mounted. On a cross pin I I3 of said ring II2 a sleeve H4 is loosely mounted. Into the sleeve II4 the upper end of a shaft II5 projects, the lower end of which carries a bolt I24. On the bolt I24 and projecting into a slot of shaft I I5 a bifurcated piece I I6 is arranged having two upwardly projecting prongs I II and I I8. The lower end of the shaft II5 forms a sleeve H9 in which the upper end of a shaft I20 is guided while the lower end is ball-shaped and rests in a bearing I2I. The latter is arranged in the cross-slide 'I (Fig. 6). The shaft H5 is provided with a screw threaded part on which a nut I22 is arranged co-operating with the prongs H1, H8. The nut I22 regulates the swinging motion of the piece II6 by allowing more or less play between the lower edge of the nut I22 and the prongs III and H8. The piece H6 is rotatably mountedflorf'studs I25 arranged in an annular member I26 rotatably mounted on radially disposed pins I2I of a sleeve I28. The latter is rotatably mounted in an arm I29 in which the sleeve I28 is adjustably mounted and in which it is held in position by a set-screw I30 (Fig. 5). The sleeve I29 is arranged in a bearing I3! by means of a bolt I29a journalled in a bearing I3! supported by arms I32 and rods I33 (Figs. 1 and 4). Between the arms I32 a bearing I35 is arranged in which the upper end of a rod I36 is journalled. The lower'end of rod I36 is rotatably mounted in a disk I31 (Fig. 4). The rod I36 is adjustably connected in radial direction with the disk I37 and maybe fixed in any radial position. The disk I31 is keyed to a shaft I38 (Fig. 4) carrying a spur wheel I39 meshing with spur wheel I40. On the shaft I4I of the wheel I46 a worm wheel I42 is fastened which may be driven by theworm I43 of the shaft IOI (Figs. 1 and 4) v On the support I60 a frame I5I is fastened in which a screw threaded spindle I52 is mounted.

On the spindle I52 a screw threaded bearingfor a roller I53 is arranged. Theroller I53 bears on a lever I55 rotatably mounted on a pin I54. On the free end of lever I55 a roller I56 is rotatably mounted which is in contact with the template II of the annular frame 8. A spring I51 which is secured at one end to table I and'at its other end to the support I00 urges the support I00 toward the template I I to bring said roller I56 into engagement with the template I'I. As shown in Fig. 4, the roller engages the contoured edge of the template I? and is moved in accordance with that contour upon rotation of the template-I1 to impart movement to the support I00. The part I53 is always in contact with the part I55, and the part I56, which is always in contact with the part II, is mounted on the part I55. If the supportIIIIl moves, the telescoped parts'of shaft 91 slide on each other.

On the slide I at least one bar I60 (Figs. 1 and 2) carrying the engraving stylus is arranged. The bar I60 is adjustably mounted on a circularfiange I6I provided with a scale. The flange I6I, is a part of slide 1. On; the bar I60 a sleeve I62 is adj ustably mounted carrying the engraving stylus I63. Two or more bars may be mounted on the flange I6I and in place of the bars I60 a rail I65 carrying a number of sleeves each adapted to receive a stylus I83 (shown in broken lines, Fig. 2) may be provided.

As shown in Fig. ,14 there may be arranged two rails I68 above the disk I2 of'the frame 8 in which a table I 63 is slidably mounted. Two parallel rails I70 are attached to tab1e.I69 and between the rails a second table III is movably mounted,

The table III is provided with holes I3 in which elements I 4 may be located to hold the plate destined to receive the engravings.

As the table I2 rotates in a right hand or left hand direction corresponding to the driving wheels of the gear drive, the plate for the engravings, fastened to the disc I2, rotates together with the disc I2. If one figure is engraved the plate with the engraving has to be shifted by on the shaft IOI.

the shifting of the table III and the engraving is more or less away from thecentre of the disc I2. Another engraving is now produced on the same plate and the two engravings form together a combined figure. A different combined figure is produced if the distance from plate is different.

As shown in Figs. 15 and 16 two parallel guide rails I90 arefastened on the disc I2 of the annular frame 8 for the following special purpose. Between the rails I90 a slide I9I is movably mounted. On a pivot I92 ofthe slide I9I a circular disk I93 is rotatably mounted. The disk I93 is provided with holes I3 adapted toreceive the clamps I4 to hold the plate to receive the engravings.

If a second engraving should'be combined'with the first engraving, the first engraving must be moved a certain distance in relation to the centre of the shaft 9. This isdone by the shifting of the slide I9I together with the turning of the disc I93.

As shown in Fig. 17 a connecting rod I80 may be connected at one end to the sleeve I28 (Figs. 5 and 6) while the other end of the rod is attached to a spur wheel NH 7 driven by a spur wheel I82 oscillates the sleeve I28 by means of the members I82, I8I and I80.

The device described works as follows:

By switching in the motor IS the latter drives, by means of the belt driver 20, 2|, the shaft 23, and by means of gears 24 and 25, the shaft 26 (Figs. 9 and 12). is rotated as well as the gear 28 coupled by the clutch 39 (Figs. and 12). By the intermediate gear 43 and spur wheel 64 on shaft 54 the spur wheels 55, 56 (Figs. 10 and 13) are driven. As shown in Fig. 11 the gear 55 meshes with the gear 60 on the shaft 62 which drives by means of the worm 63 and worm wheel 64 the shaft 9 and therewith the annular frame 8 and the table I2. The gear rotates simultaneously by the spur wheel BI the shaft80 (Fig. '10). The latter drives by means of the gears 83, 90 the shaft 9|. Either of the gears 93, 94 of shaft 9| is in mesh with one of the gears 95, 96-(Fig. 1). The rotations of the shaft 91 are transmitted by the gears I02, I05, I06 to the shaft lilloperating thereby the adjusting device I08 (Figs. 1, 5'and 6).

In the position of the parts H0, N3 of the cross-joint as shown in Fig. 5 the sleeve II4 will be turned about an axis common to the shaft I01 and said sleeve H4. The rotation is not trans: mitted to the shaft H5. If however by turning the'screw-threaded spindle I 09 the slide H0 is brought out of center it .will perform a circular movement about the axis of shaft I 01. The shaft H5 sliding in sleeve II4 transmits the gyratory movement, as it is held in the universal joint I24 to I21. The lower end of the member H6 rockingly mounted on the bolt I24 performs but an oscillatory movement in the direction of the arrow C (Fig. 6) moving the frame I to and fro in the directions shown by the arrow A (Fig. 2). By this movement of frame I the stylus I63. will cut a sine curve (Fig. 18) on the'wax of the glass plate I5 fastened to the disk I2.

By shifting the shaft 40 (Fig. 10) the key 39 may be brought in engagement with any of the spur wheels 28 to and as the rotations thereof are transmitted to the gears 44 to 52 the circumferential speed of disk I2 may be varied within wide limits and therewith the number of the periods of the sine curve during a working period. In Fig. 18 the curves formed are shown. The outer ring comprises a plurality of the periodic the centre of the The shaft IOI when rotated By the shaft 26 the gear 21 curves formed as apredetermined multiple of the periodic curves shown in the inner ring for each full turn of disk I2. If the speed of the disc I2' is changed there are cut more or lesscurves on the plate I5. The lower the speed of the disc I2 the more curves are cut on the plate I5. Each curve is produced by the movement of the frames 2 and I. By pulling knob 58 (Figs. 10 and 11) out wardly, the gears 56, (H are brought in engagement. .The number of teeth on the wheels 56, 6I are such that the sinusoidal curve. will have been finished only after five full turns of the disk I2. The engraving shown in Fig. 19 is thereby pro duced by the stylus. I03on the wax layer of disk I2. By choosing appropriate co-operating gears 56, 6! and so on the number of turns of disk I2 are determined. The diameter of the circle performed by sleeve I I4 is adjusted according to the distance of the slide IIO from the axis of shaft I01 and therefore the direction C (Fig. 6) of the shaft I20 and the direction A of the frame I will be different as well as the height of the curves.

If however the nut I22 is screwed down untilthe seat I22a comes to bear on the arms II'I,

I 50 the parts I I5, I I6, are coupled. The gyratory movement of the sleeve H4 will be transmitted to sleeve I I3, shaft I20 and to slide I. The latter can only perform a reciprocating movement in the direction shown by arrow A, (Fig. 2), the an-.

nular guide 2 carrying the frame I isforced to move in the direction shown by "arrow B. The;

frames 2, I are moving at right angles with reference to each and the stylus I03 would draw a circle if the disk I2 were stationary. The disk I2 however is turning and the stylus I63 draws loops as shown in Fig. 20. By moving the knob 08 (Fig.

10) and therewith the shaft until the bevel gear meshes with bevel gear 00, the direction of the rotation of the shafts ill, 9? of the swivel;

joint I08 and of the shaft. IE0 is reversed. The stylus I5! will now draw loops as shown in Fig; 21. By shifting the gears 3|, 82 from the position shown in Fig. 10 in such a manner as to get the gear .82 into mesh with the gear 27 the rotational speed of the shaft 00, 9|, 9'! and IDI will be reduced and the movements of the frames 2, I will be slowed. Figures 20, 21 illustrate the effects obtained, that is, a different number of loops will be produced for each full turn of the'disk I2,

By loosening the nut I22 until there is a gap between the edge I22a of the nut I22, and the arms Ill and H8 which is less than that shown in Figs. 5 and 6 the edge ,I2'2a will make contact alternately with the arms H1, H8 while the fork II5 is rotating. Themember H6 makes at each rotation a rocking motion about its pivot M4. The curve drawn by the stylus I65 which may be a sine curve or loop-like curve receives a certain break. By further loosening the nut I22 the curves, shown in Figs. 22 to 25 may be produced.

The curves shown in Fig. 25 will be produced only if the edge I 22a touches the arms II'I,.II8 but slightly and for a very short time upon each rotation of shaft I01. By loosening the screw I35 (Fig. 5) the sleeve I25 may be turned-inthe holder I29 in both directions from its middle position shown. Owing to the displacement of the parts H5, H6 in the sleeve I28 the frames 2, 1 will be moved in such a manner that the curves or loops drawn by the stylus Its-will take an oblique position with reference to the center of the figure, as shown in Fig. 26.

I While the slide H0 remains in its radialposition, the radial length of a curve produced re-,.

mains stationary. During a full turn of disk I2 the length may be varied and drawings as shown inFigs. 27 and 28 may be produced in the following manner:

The worm I43 (Figs. 1 and 4) on shaft IBI drives by the gears I42, I40, I39 the disk I3I with which the connecting rod I36 is connected. While the disk I3! is rotating the connecting rod I36 performs an up and down movement, the latter being transmitted over the members I35, I3I andl29 to the sleeve I28. The bolt I24 (Figs. and 6) is moved up and down and the leverage between sleeve H4 and the member I20 and therewith the height of the curves drawn varies. The number of changes in the dimensions of a curve during a full turn of the disk I2 may be varied by choosing gears I39, I48 of difierent diameters and by adjusting the position of the member 39 (Fig. Moreover the variation in height'of a curve may be varied by radially displacing the pin by which the connecting rod I36 is connected with disk I37.

The support I08 which is movably mounted by rollers I03 on the rails I54 is drawn to the right (Fig. 1) by a spring I51. The roller I53 is pushed on to lever I55 which rests by roller I55 on the template II. In Fig. 4 but one of many possible shapes of the cam H is shown. The support If!!! and therewith the frame I is moved in the directionof arrow A by said template II and curves as shown for instance in the Figs. 29 and 31 may be produced. By displacing the roller I53 by means of the spindle I52 the shape of the curves produced may be varied.

The stylus I63 may be placed on any point of the plate I5 by adjusting the holder Hill in the guide IBI. The shape of the curves produced by the stylus I63 will be different according to the position where the stylus I53 is placed on the plate I5. A plurality of styli I63 may be used, each tracing in a different position and each stylus will trace a different curve. By displacing be traced. To produce different patterns the slide r II is displaced on the rack I3 by means of the shaft 9. The stylus IB3 traces partly a straight line as shown in Figs. 33 to 44. To trace a pat tern as shown in Fig. 33 for instance the elements III] to N4 of the chuck I08 shown in Figs.

5 and 6 are re-set and the member I22 is screwed down on the shaft I I5. By pushing the knob 88 out of its position as shown in Fig. 10 into its other end position, the direction of rotation of the members 90 to I is reversed and the mirror image of the pattern of Fig. 33 will be traced. The said two patterns placed one above the other would produce the pattern shown in Fig. 34. In an analogous manner the pattern shown in Figs. 35 and 36 may be produced in which figures several different patterns are reproduced placed one above another. In Fig. 37 a pattern is shown which is produced by superposing or combining the patterns shown in the Figs. 38 and 39. The patterns in the said Figs. 38 and 39 are traced by means of a holder 165 for a plurality of styli I63 (Fig.2). The patterns shown in Figs. 38 and 39 are produced by the use of three and two styli. In Figs. 40 and 41 two patterns are shown in which curves are superposed and engraved and which may be reproduced with good results by any two-color printing process.

The use of the members I3I to I43 (Fig. 4) has the efiect of a regular change in the height of the curves as shown in Figs. 42 and'43. An oblique displacement of the curves shown in Fig. 42 to that shown in Fig. 43 may be effected by turning the sleeve I28 in the member I29 (Figs. 5 and 6). In Fig. 44 a pattern is shown which has been produced by Setting the members for tracing the design in Fig. 42 but by increasing the rate of movement of the table II.

If the rack I3 is displaced with reference to the slide II by means of the screw I4, the lines of the pattern are displaced similarly to the pattern in Fig. 32. By turning the table I5 (Fig. 7) about its pivot I6, patterns as illustrated in the Figs. 45 and 46 will be produced. By simultaneously using a template I9 no straight basic lines will be produced but wave lines instead in conformity with the shape of the template.

In Fig. 47 a pattern is shown in which the directions of the lines and their angular position will, by reference to a center line, vary in a regular manner. The varyin of the length of each element of the pattern may be obtained by the means described with reference to Fig. 42 and the angular variation of the lines is obtained by the device shown particularly in Fig. 17 by turning the sleeve I28 to and fro in a regular manner.

Fig. 48 is an example of a pattern which may be produced when the modified support of Fig. 14 is used. Fig. 49 is an example of a pattern which may be produced when the modified support of Figs. 16 and 17 is used. Figs. 50-55 represent other types of combined patterns which can be produced by appropriate adjustments of the machine.

What I wish to secure by United States Letters Patent is:

1. An engraving machine comprising a support including a rotatable and adjustable disc to receive a plate to be engraved, a slide, at least one stylus operatively mounted on said slide to work on said plate, means for moving said support and said stylus with respect to each other to trace figures on said plate, the aforesaid means including means for distorting the curves of the figures at predetermined places and to predetermined extents, said last mentioned means including a tiltably mounted shaft, means for moving said shaft in a circular path, a nut adjustably mounted on said shaft, a bifurcated member operatively associated with said shaft and said nut, a universal joint supporting said bifurcated member for movement in every direction, said bifurcated member having two arms cooperating with said nut to be moved thereby upon movement of said shaft in a circular path, an axially displaeeable member operatively connecting said bifurcated member and said slide to transmit the movement of said member to said slide to move said slide and said stylus with respect to said support, and means for rotating said disc including change speed gearing. 1

2. An engraving machine comprising a support including a rotatable and adjustable disc to receive a plate to be engraved, a slide, a guide mounted on said slide, a holder adjustably at-' and to predetermined extents, said last mentioned means including a tiltably mounted shaft, means for moving said shaft in a circular path, a nut adjustably mounted on said shaft, a bifurcated member operatively associated with said shaft and said nut, a universal joint supporting said bifurcated member for movement in any direction, said bifurcated member having two arms cooperating with said nut to be moved thereby upon movement of said shaft in a circular path, an axially displaceable member operatively connecting said bifurcated member and said slide to transmit the movement of said member to said slide to move said slide with respect to said support, said means for moving said shaft in a circular path including an adjustable eccentric chuck, and means for rotating said chuck, said shaft being connected to said chuck with freedom of movement in every direction, said nut bein adjustable on said shaft so as to vary the amount of operative association between said nut and said bifurcated member so that said nut is capable of transmitting the Whole or part of the 10 whole movement of the shaft to said bifurcated member and thusly to said slide, and means for rotating said disc including change speed gearing.

OSCAR BACHMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2 1,254,003 Stainkamp Jan. 15, 1918 1,269,920 Foster June 18, 1913 1,294,639 Eaton Feb. 18, 1919 1,420,319 Kelley June 20, 1922 1,763,885 Fisher June 1'7, 1930 FOREIGN PATENTS Number Country Date 271,959 Switzerland Nov., 1950 300,918 Germany Sept. 29, 1917 

